/*
 * Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#ifndef OPENSSL_TRACE_H
#define OPENSSL_TRACE_H
#pragma once

#include <openssl/bio.h>
#include <stdarg.h>

#ifdef __cplusplus
extern "C"
{
#endif

/*
 * TRACE CATEGORIES
 */

/*
 * The trace messages of the OpenSSL libraries are organized into different
 * categories. For every trace category, the application can register a separate
 * tracer callback. When a callback is registered, a so called trace channel is
 * created for this category. This channel consists essentially of an internal
 * BIO which sends all trace output it receives to the registered application
 * callback.
 *
 * The ALL category can be used as a fallback category to register a single
 * channel which receives the output from all categories. However, if the
 * application intends to print the trace channel name in the line prefix,
 * it is better to register channels for all categories separately.
 * (This is how the openssl application does it.)
 */
#define OSSL_TRACE_CATEGORY_ALL 0 /* The fallback */
#define OSSL_TRACE_CATEGORY_TRACE 1
#define OSSL_TRACE_CATEGORY_INIT 2
#define OSSL_TRACE_CATEGORY_TLS 3
#define OSSL_TRACE_CATEGORY_TLS_CIPHER 4
#define OSSL_TRACE_CATEGORY_CONF 5
#define OSSL_TRACE_CATEGORY_ENGINE_TABLE 6
#define OSSL_TRACE_CATEGORY_ENGINE_REF_COUNT 7
#define OSSL_TRACE_CATEGORY_PKCS5V2 8
#define OSSL_TRACE_CATEGORY_PKCS12_KEYGEN 9
#define OSSL_TRACE_CATEGORY_PKCS12_DECRYPT 10
#define OSSL_TRACE_CATEGORY_X509V3_POLICY 11
#define OSSL_TRACE_CATEGORY_BN_CTX 12
#define OSSL_TRACE_CATEGORY_CMP 13
#define OSSL_TRACE_CATEGORY_STORE 14
#define OSSL_TRACE_CATEGORY_DECODER 15
#define OSSL_TRACE_CATEGORY_ENCODER 16
#define OSSL_TRACE_CATEGORY_REF_COUNT 17
#define OSSL_TRACE_CATEGORY_HTTP 18
/* Count of available categories. */
#define OSSL_TRACE_CATEGORY_NUM 19
    /* KEEP THIS LIST IN SYNC with trace_categories[] in crypto/trace.c */

    /* Returns the trace category number for the given |name| */
    int OSSL_trace_get_category_num(const char *name);

    /* Returns the trace category name for the given |num| */
    const char *OSSL_trace_get_category_name(int num);

    /*
     * TRACE CONSUMERS
     */

    /*
     * Enables tracing for the given |category| by providing a BIO sink
     * as |channel|. If a null pointer is passed as |channel|, an existing
     * trace channel is removed and tracing for the category is disabled.
     *
     * Returns 1 on success and 0 on failure
     */
    int OSSL_trace_set_channel(int category, BIO *channel);

    /*
     * Attach a prefix and a suffix to the given |category|, to be printed at the
     * beginning and at the end of each trace output group, i.e. when
     * OSSL_trace_begin() and OSSL_trace_end() are called.
     * If a null pointer is passed as argument, the existing prefix or suffix is
     * removed.
     *
     * They return 1 on success and 0 on failure
     */
    int OSSL_trace_set_prefix(int category, const char *prefix);
    int OSSL_trace_set_suffix(int category, const char *suffix);

    /*
     * OSSL_trace_cb is the type tracing callback provided by the application.
     * It MUST return the number of bytes written, or 0 on error (in other words,
     * it can never write zero bytes).
     *
     * The |buffer| will always contain text, which may consist of several lines.
     * The |data| argument points to whatever data was provided by the application
     * when registering the tracer function.
     *
     * The |category| number is given, as well as a |cmd| number, described below.
     */
    typedef size_t (*OSSL_trace_cb)(const char *buffer, size_t count, int category, int cmd,
                                    void *data);
/*
 * Possible |cmd| numbers.
 */
#define OSSL_TRACE_CTRL_BEGIN 0
#define OSSL_TRACE_CTRL_WRITE 1
#define OSSL_TRACE_CTRL_END 2

    /*
     * Enables tracing for the given |category| by creating an internal
     * trace channel which sends the output to the given |callback|.
     * If a null pointer is passed as callback, an existing trace channel
     * is removed and tracing for the category is disabled.
     *
     * NOTE: OSSL_trace_set_channel() and OSSL_trace_set_callback() are mutually
     *       exclusive.
     *
     * Returns 1 on success and 0 on failure
     */
    int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data);

    /*
     * TRACE PRODUCERS
     */

    /*
     * Returns 1 if tracing for the specified category is enabled, otherwise 0
     */
    int OSSL_trace_enabled(int category);

    /*
     * Wrap a group of tracing output calls.  OSSL_trace_begin() locks tracing and
     * returns the trace channel associated with the given category, or NULL if no
     * channel is associated with the category.  OSSL_trace_end() unlocks tracing.
     *
     * Usage:
     *
     *    BIO *out;
     *    if ((out = OSSL_trace_begin(category)) != NULL) {
     *        ...
     *        BIO_fprintf(out, ...);
     *        ...
     *        OSSL_trace_end(category, out);
     *    }
     *
     * See also the convenience macros OSSL_TRACE_BEGIN and OSSL_TRACE_END below.
     */
    BIO *OSSL_trace_begin(int category);
    void OSSL_trace_end(int category, BIO *channel);

    /*
     * OSSL_TRACE* Convenience Macros
     */

    /*
     * When the tracing feature is disabled, these macros are defined to
     * produce dead code, which a good compiler should eliminate.
     */

    /*
     * OSSL_TRACE_BEGIN, OSSL_TRACE_END - Define a Trace Group
     *
     * These two macros can be used to create a block which is executed only
     * if the corresponding trace category is enabled. Inside this block, a
     * local variable named |trc_out| is defined, which points to the channel
     * associated with the given trace category.
     *
     * Usage: (using 'TLS' as an example category)
     *
     *     OSSL_TRACE_BEGIN(TLS) {
     *
     *         BIO_fprintf(trc_out, ... );
     *
     *     } OSSL_TRACE_END(TLS);
     *
     *
     * This expands to the following code
     *
     *     do {
     *         BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_TLS);
     *         if (trc_out != NULL) {
     *             ...
     *             BIO_fprintf(trc_out, ...);
     *         }
     *         OSSL_trace_end(OSSL_TRACE_CATEGORY_TLS, trc_out);
     *     } while (0);
     *
     * The use of the inner '{...}' group and the trailing ';' is enforced
     * by the definition of the macros in order to make the code look as much
     * like C code as possible.
     *
     * Before returning from inside the trace block, it is necessary to
     * call OSSL_TRACE_CANCEL(category).
     */

#if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE

#define OSSL_TRACE_BEGIN(category)                                       \
    do                                                                   \
    {                                                                    \
        BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_##category); \
                                                                         \
        if (trc_out != NULL)

#define OSSL_TRACE_END(category)                             \
    OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out); \
    }                                                        \
    while (0)

#define OSSL_TRACE_CANCEL(category) OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out)

#else

#define OSSL_TRACE_BEGIN(category) \
    do                             \
    {                              \
        BIO *trc_out = NULL;       \
        if (0)

#define OSSL_TRACE_END(category) \
    }                            \
    while (0)

#define OSSL_TRACE_CANCEL(category) ((void)0)

#endif

/*
 * OSSL_TRACE_ENABLED() - Check whether tracing is enabled for |category|
 *
 * Usage:
 *
 *     if (OSSL_TRACE_ENABLED(TLS)) {
 *         ...
 *     }
 */
#if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE

#define OSSL_TRACE_ENABLED(category) OSSL_trace_enabled(OSSL_TRACE_CATEGORY_##category)

#else

#define OSSL_TRACE_ENABLED(category) (0)

#endif

    /*
     * OSSL_TRACE*() - OneShot Trace Macros
     *
     * These macros are intended to produce a simple printf-style trace output.
     * Unfortunately, C90 macros don't support variable arguments, so the
     * "vararg" OSSL_TRACEV() macro has a rather weird usage pattern:
     *
     *    OSSL_TRACEV(category, (trc_out, "format string", ...args...));
     *
     * Where 'channel' is the literal symbol of this name, not a variable.
     * For that reason, it is currently not intended to be used directly,
     * but only as helper macro for the other oneshot trace macros
     * OSSL_TRACE(), OSSL_TRACE1(), OSSL_TRACE2(), ...
     *
     * Usage:
     *
     *    OSSL_TRACE(INIT, "Hello world!\n");
     *    OSSL_TRACE1(TLS, "The answer is %d\n", 42);
     *    OSSL_TRACE2(TLS, "The ultimate question to answer %d is '%s'\n",
     *                42, "What do you get when you multiply six by nine?");
     */

#if !defined OPENSSL_NO_TRACE && !defined FIPS_MODULE

#define OSSL_TRACEV(category, args) \
    OSSL_TRACE_BEGIN(category)      \
    BIO_printf args;                \
    OSSL_TRACE_END(category)

#else

#define OSSL_TRACEV(category, args) ((void)0)

#endif

#define OSSL_TRACE(category, text) OSSL_TRACEV(category, (trc_out, "%s", text))

#define OSSL_TRACE1(category, format, arg1) OSSL_TRACEV(category, (trc_out, format, arg1))
#define OSSL_TRACE2(category, format, arg1, arg2) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2))
#define OSSL_TRACE3(category, format, arg1, arg2, arg3) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3))
#define OSSL_TRACE4(category, format, arg1, arg2, arg3, arg4) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4))
#define OSSL_TRACE5(category, format, arg1, arg2, arg3, arg4, arg5) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5))
#define OSSL_TRACE6(category, format, arg1, arg2, arg3, arg4, arg5, arg6) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6))
#define OSSL_TRACE7(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7))
#define OSSL_TRACE8(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8))
#define OSSL_TRACE9(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \
    OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9))

#define OSSL_TRACE_STRING_MAX 80
    int OSSL_trace_string(BIO *out, int text, int full, const unsigned char *data, size_t size);
#define OSSL_TRACE_STRING(category, text, full, data, len)                            \
    OSSL_TRACE_BEGIN(category) { OSSL_trace_string(trc_out, text, full, data, len); } \
    OSSL_TRACE_END(category)

#ifdef __cplusplus
}
#endif

#endif
